This invention relates generally to novel 6-membered aromatics which are inhibitors of trypsin-like serine protease enzymes, especially factor Xa, pharmaceutical compositions containing the same, and methods of using the same as anticoagulant agents for treatment and prevention of thromboembolic disorders.
WO 96/28427 describes benzamidine anticoagulants of the formula: 
wherein Z1 and Z2 are O, N(R), S or OCH2 and the central ring may be phenyl or a variety of heterocycles. The presently claimed compounds do not contain the Z1 linker or the substitution pattern of the above compounds.
WO 95/18111 addresses fibrinogen receptor antagonists, containing basic and acidic termini, of the formula: 
wherein R1 represents the basic termini, U is an alkylene or heteroatom linker, V may be a heterocycle, and the right hand portion of the molecule represents the acidic termini. The presently claimed compounds do not contain the acidic termini of WO 95/18111.
Activated factor Xa, whose major practical role is the generation of thrombin by the limited proteolysis of prothrombin, holds a central position that links the intrinsic and extrinsic activation mechanisms in the final common pathway of blood coagulation. The generation of thrombin, the final serine protease in the pathway to generate a fibrin clot, from its precursor is amplified by formation of prothrombinase complex (factor Xa, factor V, Ca2+ and phospholipid). Since it is calculated that one molecule of factor Xa can generate 138 molecules of thrombin (Elodi, S., Varadi, K.: Optimization of conditions for the catalytic effect of the factor IXa-factor VIII Complex: Probable role of the complex in the amplification of blood coagulation. Thromb. Res. 1979, 15, 617-629), inhibition of factor Xa may be more efficient than inactivation of thrombin in interrupting the blood coagulation system.
Therefore, efficacious and specific inhibitors of factor Xa are needed as potentially valuable therapeutic agents for the treatment of thromboembolic disorders. It is thus desirable to discover new factor Xa inhibitors.
Accordingly, one object of the present invention is to provide novel 6-membered aromatics which are useful as factor Xa inhibitors or pharmaceutically acceptable salts or prodrugs thereof.
It is another object of the present invention to provide pharmaceutical compositions comprising a pharmaceutically acceptable carrier and a therapeutically effective amount of at least one of the compounds of the present invention or a pharmaceutically acceptable salt or prodrug form thereof.
It is another object of the present invention to provide a method for treating thromboembolic disorders comprising administering to a host in need of such treatment a therapeutically effective amount of at least one of the compounds of the present invention or a pharmaceutically acceptable salt or prodrug form thereof.
These and other objects, which will become apparent during the following detailed description, have been achieved by the inventors""discovery that compounds of formula (I): 
or pharmaceutically acceptable salt or prodrug forms thereof, wherein A, B, D, E, M, R1a, R1b, and Z are defined below, are effective factor Xa inhibitors.
[1] Thus, in a first embodiment, the present invention provides novel compounds of formula I: 
xe2x80x83or a stereoisomer or pharmaceutically acceptable salt form thereof, wherein;
ring M contains from 0-4 N atoms;
D is selected from CN, C(xe2x95x90NR7)NR8R9, NHC(xe2x95x90NR7)NR8R9, NR8CH(xe2x95x90NR7), C(O)NR8R9, and (CR8R9)tNR8R9;
E is selected from phenyl, 2-pyridyl, 4-pyridyl, pyrimidyl, and piperidinyl substituted with 1 R;
R is selected from H, F, Cl, Br, I, OR3, SR3, CO2R3, NO2, and CH2OR3, and (CR8R9)tNR8R9;
alternatively, E and R combine to form methylenedioxy or ethylenedioxy;
Z is selected from a bond, C1-4 alkylene, (CH2)rO(CH2)r, (CH2)rNR3(CH2)r, (CH2)rC(O)(CH2)r, (CH2)rC(O)O(CH2)r, (CH2)rOC(O)(CH2)r, (CH2)rC(O)NR3(CH2)r, (CH2)rNR3C(O)(CH2)r, (CH2)rOC(O)O(CH2)r, (CH2)rOC(O)NR3(CH2)r, (CH2)rNR3C(O)O(CH2)r, (CH2)rNR3C(O)NR3(CH2)r, (CH2)rS(O)p(CH2)r, (CH2)rSO2NR3(CH2)r, (CH2)rNR3SO2(CH2)r, and (CH2)rNR3SO2NR3(CH2)r, provided that Z does not form a Nxe2x80x94-N, Nxe2x80x94O, Nxe2x80x94S, NCH2N, NCH2O, or NCH2S bond with ring M or group A;
R1a and R1b are independently absent or selected from xe2x80x94(CH2)rxe2x80x94R1xe2x80x2, xe2x80x94CHxe2x95x90CHxe2x80x94R1xe2x80x2, NCH2R1xe2x80x3, OCH2R1xe2x80x3, SCH2R1xe2x80x3, NH(CH2)2(CH2)tR1xe2x80x2, O(CH2)2(CH2)tR1xe2x80x2, and S(CH2)2(CH2)tR1xe2x80x2;
alternatively, R1a and R1b, when attached to adjacent carbon atoms, together with the atoms to which they are attached form a 5-8 membered saturated, partially saturated or unsaturated ring substituted with 0-2 R4 and which contains from 0-2 heteroatoms selected from the group consisting of N, O, and S;
alternatively, when Z is C(O)NH and R1a is attached to a ring carbon adjacent to Z, then R1a is a C(O) which replaces the amide hydrogen of Z to form a cyclic imide;
R1xe2x80x2 is selected from H, C1-3 alkyl, F, Cl, Br, I, xe2x80x94CN, xe2x80x94CHO, (CF2)rCF3, (CH2)rOR2, NR2R2a, C(O)R2c, OC(O)R2, (CF2)rCO2R2c, S(O)pR2b, NR2(CH2)rOR2, CH(xe2x95x90NR2c)NR2R2a, NR2C(O)R2b, NR2C(O)NHR2b, NR2C(O)2R2a, OC(O)NR2aR2b, C(O)NR2R2a, C(O)NR2(CH2)rOR2, SO2NR2R2a, NR2SO2R2b, C3-6 carbocyclic residue substituted with 0-2 R4, and 5-10 membered heterocyclic system containing from 1-4 heteroatoms selected from the group consisting of N, O, and S substituted with 0-2 R4;
R1xe2x80x3 is selected from H, CH(CH2OR2)2, C(O)R2c, C(O)NR2R2a, S(O)R2b, S(O)2R2b, and SO2NR2R2a;
R2, at each occurrence, is selected from H, CF3, C1-6 alkyl, benzyl, C3-6 carbocyclic residue substituted with 0-2 R4b, and 5-6 membered heterocyclic system containing from 1-4 heteroatoms selected from the group consisting of N, O, and S substituted with 0-2 R4b;
R2a, at each occurrence, is selected from H, CF3, C1-6 alkyl, benzyl, phenethyl, C3-6 carbocyclic residue substituted with 0-2 R4b, and 5-6 membered heterocyclic system containing from 1-4 heteroatoms selected from the group consisting of N, O, and S substituted with 0-2 R4b;
R2b, at each occurrence, is selected from CF3, C1-4 alkoxy, C1-6 alkyl, benzyl, C3-6 carbocyclic residue substituted with 0-2 R4b, and 5-6 membered heterocyclic system containing from 1-4 heteroatoms selected from the group consisting of N, O, and S substituted with 0-2 R4b;
R2c, at each occurrence, is selected from CF3, OH, C1-4 alkoxy, C1-6 alkyl, benzyl, C3-6 carbocyclic residue substituted with 0-2 R4b, and 5-6 membered heterocyclic system containing from 1-4 heteroatoms selected from the group consisting of N, O, and S substituted with 0-2 R4b;
alternatively, R2 and R2a, together with the atom to which they are attached, combine to form a 5 or 6 membered saturated, partially saturated or unsaturated ring substituted with 0-2 R4b and containing from 0-1 additional heteroatoms selected from the group consisting of N, O, and S;
R3, at each occurrence, is selected from H, C1-4 alkyl, and phenyl;
R3a, at each occurrence, is selected from H, C1-4 alkyl, and phenyl;
R3b, at each occurrence, is selected from H, C1-4 alkyl, and phenyl;
R3c, at each occurrence, is selected from C1-4 alkyl, and phenyl;
A is selected from:
C3-10 carbocyclic residue substituted with 0-2 R4, and
5-10 membered heterocyclic system containing from 1-4 heteroatoms selected from the group consisting of N, O, and S substituted with 0-2 R4;
B is selected from: H, Y, and Xxe2x80x94Y;
X is selected from C1-4 alkylene, xe2x80x94CR2(CR2R2b)(CH2)txe2x80x94, xe2x80x94C(O)xe2x80x94, xe2x80x94C(xe2x95x90NR1xe2x80x3)xe2x80x94, xe2x80x94CR2(NR1xe2x80x3R2)xe2x80x94, xe2x80x94CR2(OR2)xe2x80x94, xe2x80x94CR2(SR2)xe2x80x94, xe2x80x94C(O)CR2R2axe2x80x94, xe2x80x94CR2R2aC(O), xe2x80x94S(O)pxe2x80x94, xe2x80x94S(O)pCR2R2axe2x80x94, xe2x80x94CR2R2aS(O)pxe2x80x94, xe2x80x94S(O)2NR2xe2x80x94, xe2x80x94NR2S(O)2xe2x80x94, xe2x80x94NR2S(O)2CR2R2axe2x80x94, xe2x80x94CR2R2aS(O)2NR2xe2x80x94, xe2x80x94NR2S(O)2NR2xe2x80x94, xe2x80x94C(O)NR2xe2x80x94, xe2x80x94NR2C(O)xe2x80x94, xe2x80x94C(O)NR2CR2R2axe2x80x94, xe2x80x94NR2C(O)CR2R2axe2x80x94, xe2x80x94CR2R2aC(O)NR2xe2x80x94, xe2x80x94CR2R2aNR2C(O)xe2x80x94, xe2x80x94NR2C(O)Oxe2x80x94, xe2x80x94OC(O)NR2xe2x80x94, xe2x80x94NR2C(O)NR2xe2x80x94, xe2x80x94NR2xe2x80x94, xe2x80x94NR2CR2R2axe2x80x94, xe2x80x94CR2R2aNR2xe2x80x94, O, xe2x80x94CR2R2aOxe2x80x94, and xe2x80x94OCR2R2axe2x80x94;
Y is selected from:
(CH2)rNR2R2a, provided that Xxe2x80x94Y do not form a Nxe2x80x94N, Oxe2x80x94N, or Sxe2x80x94N bond,
C3-10 carbocyclic residue substituted with 0-2 R4a, and
5-10 membered heterocyclic system containing from 1-4 heteroatoms selected from the group consisting of N, O, and S substituted with 0-2 R4a;
R4, at each occurrence, is selected from H, xe2x95x90O, (CH2)rOR2, F, Cl, Br, I, C1-4 alkyl, xe2x80x94CN, NO2, (CH2)rNR2R2a, (CH2)rC(O)R2c, NR2C(O)R2b, C(O)NR2R2a, NR2C(O)NR2R2a, CH(xe2x95x90NR2)NR2R2a, CH(xe2x95x90NS(O)2R5)NR2R2a, NHC(xe2x95x90NR2)NR2R2a, C(O)NHC(xe2x95x90NR2)NR2R2a, SO2NR2R2a, NR2SO2NR2R2a, NR2SO2xe2x80x94C1-4 alkyl, NR2SO2R5, S(O)pR5, (CF2)rCF3, NCH2R1xe2x80x3, OCH2R1xe2x80x3, SCH2R1xe2x80x3, N(CH2)2(CH2)tR1xe2x80x2, O(CH2)2(CH2)tR1xe2x80x2, and S(CH2)2(CH2)tR1xe2x80x2;
alternatively, one R4 is a 5-6 membered aromatic heterocycle containing from 1-4 heteroatoms selected from the group consisting of N, O, and S;
R4a, at each occurrence, is selected from H, xe2x95x90O, (CH2)rOR2, (CH2)rxe2x80x94F, (CH2)rxe2x80x94Br, (CH2)rxe2x80x94Cl, I, C1-4 alkyl, xe2x80x94CN, NO2, (CH2)rNR2R2a, (CH2)rNR2R2b, (CH2)rC(O)R2c, NR2C(O)R2b, C(O)NR2R2a, C(O)NH(CH2)2NR2R2a, NR2C(O)NR2R2a, CH(xe2x95x90NR2)NR2R2a, NHC(xe2x95x90NR2)NR2R2a, SO2NR2R2a, NR2SO2NR2R2a, NR2SO2xe2x80x94C1-4 alkyl, C(O)NHSO2xe2x80x94C1-4 alkyl, NR2SO2R5, S(O)pR5, and (CF2)rCF3;
alternatively, one R4a is a 5-6 membered aromatic heterocycle containing from 1-4 heteroatoms selected from the group consisting of N, O, and S and substituted with 0-1 R5;
R4b, at each occurrence, is selected from H, xe2x95x90O, (CH2)rOR3, F, Cl, Br, I, C1-4 alkyl, xe2x80x94CN, NO2, (CH2)rNR3R3a, (CH2)rC(O)R3, (CH2)rC(O)OR3c, NR3C(O)R3a, C(O)NR3R3a, NR3C(O)NR3R3a, CH(xe2x95x90NR3)NR3R3a, NH3C(xe2x95x90NR3)NR3R3a, SO2NR3R3a, NR3SO2NR3R3a, NR3SO2xe2x80x94C1-4 alkyl, NR3SO2CF3, NR3SO2-phenyl, S(O)pCF3, S(O)pxe2x80x94C1-4 alkyl, S(O)p-phenyl, and (CF2)rCF3;
R5, at each occurrence, is selected from CF3, C1-6 alkyl, phenyl substituted with 0-2 R6, and benzyl substituted with 0-2 R6;
R6, at each occurrence, is selected from H, OH, (CH2)rOR2, F, Cl, Br, I, C1-4 alkyl, CN, NO2, (CH2)rNR2R2a, (CH2)rC(O)R2b, NR2C(O)R2b, NR2C(O)NR2R2a, CH(xe2x95x90NH)NH2, NHC(xe2x95x90NH)NH2, SO2NR2R2a, NR2SO2NR2R2a, and NR2SO2C1-4 alkyl;
R7, at each occurrence, is selected from H, OH, C1-6 alkyl, C1-6 alkylcarbonyl, C1-6 alkoxy, C1-4 alkoxycarbonyl, (CH2)n-phenyl, C6-10 aryloxy, C6-10 aryloxycarbonyl, C6-10 arylmethylcarbonyl, C1-4 alkylcarbonyloxy C1-4 alkoxycarbonyl, C6-10 arylcarbonyloxy C1-4 alkoxycarbonyl, C1-6 alkylaminocarbonyl, phenylaminocarbonyl, and phenyl-C1-4 alkoxycarbonyl;
R8, at each occurrence, is selected from H, C1-6 alkyl and (CH2)n-phenyl;
alternatively, R7 and R8 combine to form a 5 or 6 membered saturated, ring which contains from 0-1 additional heteroatoms selected from the group consisting of N, O, and S;
R9, at each occurrence, is selected from H, C1-6 alkyl and (CH2)n-phenyl;
n is selected from 0, 1, 2, and 3;
m is selected from 0, 1, and 2;
p is selected from 0, 1, and 2;
r is selected from 0, 1, 2, and 3;
s is selected from 0, 1, and 2; and,
t is selected from 0 and 1.
[2] In a preferred embodiment, the present invention provides novel compounds of formulae Ia-Io: 
xe2x80x83wherein:
Z is selected from a bond, CH2O, OCH2, CH2NH, NHCH2, CH2C(O), C(O)CH2, C(O)NH, C(O)NH, CH2S(O)2, S(O)2(CH2), SO2NH, and SO2NH;
B is selected from: Y, Xxe2x80x94Y, and NR2R2a;
Y is selected from one of the following carbocyclic and heterocyclic systems which are substituted with 0-2 R4a;
phenyl, piperidinyl, piperazinyl, pyridyl, pyrimidyl, furanyl, morpholinyl, thiophenyl, pyrrolyl, pyrrolidinyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, pyrazolyl, imidazolyl, oxadiazole, thiadiazole, triazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,2,3-triazole, 1,2,4-triazole, 1,2,5-triazole, 1,3,4-triazole, benzofuran, benzothiofuran, indole, benzimidazole, benzoxazole, benzthiazole, indazole, benzisoxazole, benzisothiazole, and isoindazole;
Y may also be selected from the following bicyclic heteroaryl ring systems: 
K is selected from O, S, NH, and N.
[3] In a more preferred embodiment, the present invention provides novel compounds of formulae: 
xe2x80x83wherein:
D is selected from C(xe2x95x90NR7)NR8R9 and (CR8R9)tNR8R9;
R is selected from H, F, Cl, OR3, CH2R3, CH2NH2;
A is selected from:
piperidinyl,
piperazinyl,
C5-6 carbocyclic residue substituted with 0-2 R4, and
5-6 membered heteroaryl containing from 1-4 heteroatoms selected from the group consisting of N, O, and S substituted with 0-2 R4;
Y is selected from one of the following carbocyclic and heterocyclic systems which are substituted with 0-2 R4a;
phenyl, piperidinyl, piperazinyl, pyridyl, pyrimidyl, furanyl, morpholinyl, thiophenyl, pyrrolyl, pyrrolidinyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, pyrazolyl, imidazolyl, benzimidazolyl, oxadiazole, thiadiazole, triazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,2,3-triazole, 1,2,4-triazole, 1,2,5-triazole, and 1,3,4-triazole.
[4] In an even more preferred embodiment, the present invention provides novel compounds wherein:
E is phenyl;
D is selected from C(xe2x95x90NH)NH2 and CH2NH2;
R is selected from H, F, Cl, and Br;
A is selected from:
C5-6 carbocyclic residue substituted with 0-2 R4, and
5-6 membered heteroaryl containing from 1-3 heteroatoms selected from the group consisting of N, O, and S substituted with 0-2 R4;
Y is selected from one of the following carbocyclic and heterocyclic systems which are substituted with 0-2 R4a;
phenyl, piperidinyl, piperazinyl, pyridyl, pyrimidyl, furanyl, morpholinyl, thiophenyl, pyrrolyl, pyrrolidinyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, pyrazolyl, imidazolyl, benzimidazolyl, oxadiazole, thiadiazole, triazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,2,3-triazole, 1,2,4-triazole, 1,2,5-triazole, and 1,3,4-triazole;
R2, at each occurrence, is selected from H, CF3, C1-6 alkyl, benzyl, C5-6 carbocyclic residue substituted with 0-2 R4b, and 5-6 membered heterocyclic system containing from 1-4 heteroatoms selected from the group consisting of N, O, and S substituted with 0-2 R4b;
R2a, at each occurrence, is selected from H, CF3, C1-6 alkyl, benzyl, phenethyl, C5-6 carbocyclic residue substituted with 0-2 R4b, and 5-6 membered heterocyclic system containing from 1-4 heteroatoms selected from the group consisting of N, O, and S substituted with 0-2 R4b;
R2b, at each occurrence, is selected from CF3, C1-4 alkoxy, C1-6 alkyl, benzyl, C5-6 carbocyclic residue substituted with 0-2 R4b, and 5-6 membered heterocyclic system containing from 1-4 heteroatoms selected from the group consisting of N, O, and S substituted with 0-2 R4b;
R2c, at each occurrence, is selected from CF3, OH, C1-4 alkoxy, C1-6 alkyl, benzyl, C5-6 carbocyclic residue substituted with 0-2 R4b, and 5-6 membered heterocyclic system containing from 1-4 heteroatoms selected from the group consisting of N, O, and S substituted with 0-2 R4b;
alternatively, R2 and R2a, together with the atom to which they are attached, combine to form a ring selected from imidazolyl, morpholino, piperazinyl, pyridyl, and pyrrolidinyl, substituted with 0-2 R4b;
R4, at each occurrence, is selected from H, xe2x95x90O, OR2, CH2OR2, F, Cl, C1-4 alkyl, NR2R2a, CH2NR2R2a, C(O)R2c, CH2C(O)R2c, C(O)NR2R2a, CH(xe2x95x90NR2)NR2R2a, CH(xe2x95x90NS(O)2R5)NR2R2a, SO2NR2R2a, NR2SO2xe2x80x94C1-4 alkyl, S(O)2R5, and CF3 
provided that if B is H, then R4 is other than tetrazole, C(O)-alkoxy, and C(O)NR2R2a;
R4a, at each occurrence, is selected from H, xe2x95x90O, (CH2)rOR2, F, Cl, C1-4 alkyl, NR2R2a, CH2NR2R2a, NR2R2b, CH2NR2R2b, (CH2)rC(O)R2c, NR2C(O)R2b, C(O)NR2R2a, C(O)NH(CH2)2NR2R2a, NR2C(O)NR2R2a, SO2NR2R2a, S(O)2R5, and CF3; and,
R4b, at each occurrence, is selected from H, xe2x95x90O, (CH2)rOR3, F, Cl, C1-4 alkyl, NR3R3a, CH2NR3R3a, C(O)R3, CH2C(O)R3, C(O)OR3c, C(O)NR3R3a, CH(xe2x95x90NR3)NR3R3a, SO2NR3R3a, NR3SO2xe2x80x94C1-4 alkyl, NR3SO2CF3, NR3SO2-phenyl, S(O)2CF3, S(O)2xe2x80x94C1-4 alkyl, S(O)2-phenyl, and CF3.
[5] In a further preferred embodiment, the present invention provides novel compounds selected from:
N-(2xe2x80x2-Aminosulfonyl-[1,1xe2x80x2]biphen-4-yl)-2-(3xe2x80x2-amidinophenyl)nicotinamide;
N-[5-(2-aminosulfonyl)phenylpyrid-2-yl]-2-(3xe2x80x2-amidinophenyl)nicotinamide;
N-[5-(2-t-butylaminosulfonyl)phenylpyrid-2-yl]-2-(3xe2x80x2-amidinophenyl)nicotinamide; and,
N-[5-(2-aminosulfonyl)phenylpyrid-2-yl]-2-(3xe2x80x2-carboxamidophenyl)nicotinamide;
or a pharmaceutically acceptable salt thereof.
In a second embodiment, the present invention provides novel pharmaceutical compositions, comprising: a pharmaceutically acceptable carrier and a therapeutically effective amount of a compound of formula (I) or a pharmaceutically acceptable salt form thereof.
In a third embodiment, the present invention provides a novel method for treating or preventing a thromboembolic disorder, comprising: administering to a patient in need thereof a therapeutically effective amount of a compound of formula (I) or a pharmaceutically acceptable salt form thereof.
The compounds herein described may have asymmetric centers. Compounds of the present invention containing an asymmetrically substituted atom may be isolated in optically active or racemic forms. It is well known in the art how to prepare optically active forms, such as by resolution of racemic forms or by synthesis from optically active starting materials. Many geometric isomers of olefins, Cxe2x95x90N double bonds, and the like can also be present in the compounds described herein, and all such stable isomers are contemplated in the present invention. Cis and trans geometric isomers of the compounds of the present invention are described and may be isolated as a mixture of isomers or as separated isomeric forms. All chiral, diastereomeric, racemic forms and all geometric isomeric forms of a structure are intended, unless the specific stereochemistry or isomeric form is specifically indicated.
The term xe2x80x9csubstituted,xe2x80x9d as used herein, means that any one or more hydrogens on the designated atom is replaced with a selection from the indicated group, provided that the designated atom""s normal valency is not exceeded, and that the substitution results in a stable compound. When a substitent is keto (i.e., xe2x95x90O), then 2 hydrogens on the atom are replaced. Keto substituents are not present on aromatic moieties.
The present invention is intended to include all isotopes of atoms occurring in the present compounds. Isotopes include those atoms having the same atomic number but different mass numbers. By way of general example and without limitation, isotopes of hydrogen include tritium and deuterium. Isotopes of carbon include C-13 and C-14.
When any variable (e.g., R6) occurs more than one time in any constituent or formula for a compound, its definition at each occurrence is independent of its definition at every other occurrence. Thus, for example, if a group is shown to be substituted with 0-2 R6, then said group may optionally be substituted with up to two R6 groups and R6 at each occurrence is selected independently from the definition of R6. Also, combinations of substituents and/or variables are permissible only if such combinations result in stable compounds.
When a bond to a substituent is shown to cross a bond connecting two atoms in a ring, then such substituent may be bonded to any atom on the ring. When a substituent is listed without indicating the atom via which such substituent is bonded to the rest of the compound of a given formula, then such substituent may be bonded via any atom in such substituent. Combinations of substituents and/or variables are permissible only if such combinations result in stable compounds.
As used herein, xe2x80x9calkylxe2x80x9d is intended to include both branched and straight-chain saturated aliphatic hydrocarbon groups having the specified number of carbon atoms. Examples of alkyl include, but are not limited to, methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, t-butyl, n-pentyl, and s-pentyl. xe2x80x9cHaloalkylxe2x80x9d is intended to include both branched and straight-chain saturated aliphatic hydrocarbon groups having the specified number of carbon atoms, substituted with 1 or more halogen (for example xe2x80x94CvFw where v=1 to 3 and w=1 to (2v+1)). Examples of haloalkyl include, but are not limited to, trifluoromethyl, trichloromethyl, pentafluoroethyl, and pentachloroethyl. xe2x80x9cAlkoxyxe2x80x9d represents an alkyl group as defined above with the indicated number of carbon atoms attached through an oxygen bridge. Examples of alkoxy include, but are not limited to, methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, s-butoxy, t-butoxy, n-pentoxy, and s-pentoxy. xe2x80x9cCycloalkylxe2x80x9d is intended to include saturated ring groups, such as cyclopropyl, cyclobutyl, or cyclopentyl. Alkenylxe2x80x9d is intended to include hydrocarbon chains of either a straight or branched configuration and one or more unsaturated carbon-carbon bonds which may occur in any stable point along the chain, such as ethenyl, propenyl and the like. xe2x80x9cAlkynylxe2x80x9d is intended to include hydrocarbon chains of either a straight or branched configuration and one or more triple carbon-carbon bonds which may occur in any stable point along the chain, such as ethynyl, propynyl and the like.
xe2x80x9cHaloxe2x80x9d or xe2x80x9chalogenxe2x80x9d as used herein refers to fluoro, chloro, bromo, and iodo; and xe2x80x9ccounterionxe2x80x9d is used to represent a small, negatively charged species such as chloride, bromide, hydroxide, acetate, sulfate, and the like.
As used herein, xe2x80x9ccarbocyclexe2x80x9d or xe2x80x9ccarbocyclic residuexe2x80x9d is intended to mean any stable 3- to 7-membered monocyclic or bicyclic or 7- to 13-membered bicyclic or tricyclic, any of which may be saturated, partially unsaturated, or aromatic. Examples of such carbocycles include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, adamantyl, cyclooctyl, [3.3.0]bicyclooctane, [4.3.0]bicyclononane, [4.4.0]bicyclodecane, [2.2.2]bicyclooctane, fluorenyl, phenyl, naphthyl, indanyl, adamantyl, or tetrahydronaphthyl.
As used herein, the term xe2x80x9cheterocyclexe2x80x9d or xe2x80x9cheterocyclic systemxe2x80x9d is intended to mean a stable 5- to 7-membered monocyclic or bicyclic or 7- to 10-membered bicyclic heterocyclic ring which is saturated partially unsaturated or unsaturated (aromatic), and which consists of carbon atoms and from 1 to 4 heteroatoms independently selected from the group consisting of N, O and S and including any bicyclic group in which any of the above-defined heterocyclic rings is fused to a benzene ring. The nitrogen and sulfur heteroatoms may optionally be oxidized. The heterocyclic ring may be attached to its pendant group at any heteroatom or carbon atom which results in a stable structure. The heterocyclic rings described herein may be substituted on carbon or on a nitrogen atom if the resulting compound is stable. If specifically noted, a nitrogen in the heterocycle may optionally be quaternized. It is preferred that when the total number of S and O atoms in the heterocycle exceeds 1, then these heteroatoms are not adjacent to one another. It is preferred that the total number of S and O atoms in the heterocycle is not more than 1. As used herein, the term xe2x80x9caromatic heterocyclic systemxe2x80x9d is intended to mean a stable 5- to 7-membered monocyclic or bicyclic or 7- to 10-membered bicyclic heterocyclic aromatic ring which consists of carbon atoms and from 1 to 4 heterotams independently selected from the group consisting of N, O and S. It is preferred that the total number of S and O atoms in the aromatic heterocycle is not more than 1.
Examples of heterocycles include, but are not limited to, acridinyl, azocinyl, benzimidazolyl, benzofuranyl, benzothiofuranyl, benzothiophenyl, benzoxazolyl, benzthiazolyl, benztriazolyl, benztetrazolyl, benzisoxazolyl, benzisothiazolyl, benzimidazolinyl, carbazolyl, 4aH-carbazolyl, carbolinyl, chromanyl, chromenyl, cinnolinyl, decahydroquinolinyl, 2H,6H-1,5,2-dithiazinyl, dihydrofuro[2,3-b]tetrahydrofuran, furanyl, furazanyl, imidazolidinyl, imidazolinyl, imidazolyl, 1H-indazolyl, indolenyl, indolinyl, indolizinyl, indolyl, 3H-indolyl, isobenzofuranyl, isochromanyl, isoindazolyl, isoindolinyl, isoindolyl, isoquinolinyl, isothiazolyl, isoxazolyl, morpholinyl, naphthyridinyl, octahydroisoquinolinyl, oxadiazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,3,4-oxadiazolyl, oxazolidinyl, oxazolyl, oxazolidinyl, pyrimidinyl, phenanthridinyl, phenanthrolinyl, phenazinyl, phenothiazinyl, phenoxathiinyl, phenoxazinyl, phthalazinyl, piperazinyl, piperidinyl, pteridinyl, purinyl, pyranyl, pyrazinyl, pyrazolidinyl, pyrazolinyl, pyrazolyl, pyridazinyl, pyridooxazole, pyridoimidazole, pyridothiazole, pyridinyl, pyridyl, pyrimidinyl, pyrrolidinyl, pyrrolinyl, 2H-pyrrolyl, pyrrolyl, quinazolinyl, quinolinyl, 4H-quinolizinyl, quinoxalinyl, quinuclidinyl, tetrahydrofuranyl, tetrahydroisoquinolinyl, tetrahydroquinolinyl, 6H-1,2,5-thiadiazinyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,2,5-thiadiazolyl, 1,3,4-thiadiazolyl, thianthrenyl, thiazolyl, thienyl, thienothiazolyl, thienooxazolyl, thienoimidazolyl, thiophenyl, triazinyl, 1,2,3-triazolyl, 1,2,4-triazolyl, 1,2,5-triazolyl, 1,3,4-triazolyl, and xanthenyl. Preferred heterocycles include, but are not limited to, pyridinyl, furanyl, thienyl, pyrrolyl, pyrazolyl, pyrrolidinyl, imidazolyl, indolyl, benzimidazolyl, 1H-indazolyl, oxazolidinyl, benzotriazolyl, benzisoxazolyl, oxindolyl, benzoxazolinyl, or isatinoyl. Also included are fused ring and spiro compounds containing, for example, the above heterocycles.
The phrase xe2x80x9cpharmaceutically acceptablexe2x80x9d is employed herein to refer to those compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio.
As used herein, xe2x80x9cpharmaceutically acceptable saltsxe2x80x9d refer to derivatives of the disclosed compounds wherein the parent compound is modified by making acid or base salts thereof. Examples of pharmaceutically acceptable salts include, but are not limited to, mineral or organic acid salts of basic residues such as amines; alkali or organic salts of acidic residues such as carboxylic acids; and the like. The pharmaceutically acceptable salts include the conventional non-toxic salts or the quaternary ammonium salts of the parent compound formed, for example, from non-toxic inorganic or organic acids. For example, such conventional non-toxic salts include those derived from inorganic acids such as hydrochloric, hydrobromic, sulfuric, sulfamic, phosphoric, nitric and the like; and the salts prepared from organic acids such as acetic, propionic, succinic, glycolic, stearic, lactic, malic, tartaric, citric, ascorbic, pamoic, maleic, hydroxymaleic, phenylacetic, glutamic, benzoic, salicylic, sulfanilic, 2-acetoxybenzoic, fumaric, toluenesulfonic, methanesulfonic, ethane disulfonic, oxalic, isethionic, and the like.
The pharmaceutically acceptable salts of the present invention can be synthesized from the parent compound which contains a basic or acidic moiety by conventional chemical methods. Generally, such salts can be prepared by reacting the free acid or base forms of these compounds with a stoichiometric amount of the appropriate base or acid in water or in an organic solvent, or in a mixture of the two; generally, nonaqueous media like ether, ethyl acetate, ethanol, isopropanol, or acetonitrile are preferred. Lists of suitable salts are found in Remington""s Pharmaceutical Sciences, 17th ed., Mack Publishing Company, Easton, Pa., 1985, p. 1418, the disclosure of which is hereby incorporated by reference.
xe2x80x9cProdrugsxe2x80x9d are intended to include any covalently bonded carriers which release the active parent drug according to formula (I) in vivo when such prodrug is administered to a mammalian subject. Prodrugs of a compound of formula (I) are prepared by modifying functional groups present in the compound in such a way that the modifications are cleaved, either in routine manipulation or in vivo, to the parent compound. Prodrugs include compounds of formula (I) wherein a hydroxy, amino, or sulfhydryl group is bonded to any group that, when the prodrug or compound of formula (I) is administered to a mammalian subject, cleaves to form a free hydroxyl, free amino, or free sulfhydryl group, respectively. Examples of prodrugs include, but are not limited to, acetate, formate and benzoate derivatives of alcohol and amine functional groups in the compounds of formula (I), and the like. Preferred prodrugs are amidine prodrugs wherein D is C(xe2x95x90NR7)NH2, and R7 is selected from OH, C1-4 alkoxy, C6-10 aryloxy, C1-4 alkoxycarbonyl, C6-10 aryloxycarbonyl, C6-10 arylmethylcarbonyl, C1-4 alkylcarbonyloxy C1-4 alkoxycarbonyl, and C6-10 arylcarbonyloxy C1-4 alkoxycarbonyl. More preferred prodrugs are where R7 is OH, methoxy, ethoxy, benzyloxycarbonyl, methoxycarbonyl, and methylcarbonyloxymethoxycarbonyl.
xe2x80x9cStable compoundxe2x80x9d and xe2x80x9cstable structurexe2x80x9d are meant to indicate a compound that is sufficiently robust to survive isolation to a useful degree of purity from a reaction mixture, and formulation into an efficacious therapeutic agent.
xe2x80x9cSubstitutedxe2x80x9d is intended to indicate that one or more hydrogens on the atom indicated in the expression using xe2x80x9csubstitutedxe2x80x9d is replaced with a selection from the indicated group(s), provided that the indicated atom""s normal valency is not exceeded, and that the substitution results in a stable compound. When a substituent is keto (i.e., xe2x95x90O) group, then 2 hydrogens on the atom are replaced.
xe2x80x9cTherapeutically effective amountxe2x80x9d is intended to include an amount of a compound of the present invention or an amount of the combination of compounds claimed effective to inhibit HIV infection or treat the symptoms of HIV infection in a host. The combination of compounds is preferably a synergistic combination. Synergy, as described for example by Chou and Talalay, Adv. Enzyme Regul. 22:27-55 (1984), occurs when the effect (in this case, inhibition of HIV replication) of the compounds when administered in combination is greater than the additive effect of the compounds when administered alone as a single agent. In general, a synergistic effect is most clearly demonstrated at suboptimal concentrations of the compounds. Synergy can be in terms of lower cytotoxicity, increased antiviral effect, or some other beneficial effect of the combination compared with the individual components.
The compounds of the present invention can be prepared in a number of ways known to one skilled in the art of organic synthesis. The compounds of the present invention can be synthesized using the methods described below, together with synthetic methods known in the art of synthetic organic chemistry, or variations thereon as appreciated by those skilled in the art. Preferred methods include, but are not limited to, those described below. The reactions are performed in a solvent appropriate to the reagents and materials employed and suitable for the transformations being effected. It will sometimes require a judgment to modify the order of synthetic steps or to select one particular process scheme over another in order to obtain a desired compound of the invention. It will also be recognized that another major consideration in the planning of any synthetic route in this field is the judicious choice of the protecting group used for the protection of the reactive functional groups present in the compounds described in this invention. An authoritative account describing the many alternatives to the trained practitioner is Greene and Wuts (Protective Groups in Organic Chemistry, Wiley and Sons, 1991). All references cited herein are hereby incorporated in their entirety herein by reference. Compounds of this invention where B is either a carbocyclic or heterocyclic residue as defined in Formula 1 are coupled to A as shown generically and by specific example in Schemes 1 and 2, respectively. Either or both of A and B may be substituted with 0-2 R4. W is defined as a suitable protected nitrogen, such as NO2 or NHBOC; a protected sulfur, such as S-tBu or SMOM; or a methyl ester. Halogen-metal exchange of the bromine in bromo-B with n-butyl lithium, quenching with triisopropyl borate and acidic hydrolysis gives the required boronic acid, Bxe2x80x94B(OH)2. The Wxe2x80x94Axe2x80x94Br subunit may be already linked to ring M before the Suzuki coupling reaction. Deprotection provides the complete subunit. 
Scheme 2 describes a typical example of how the Axe2x80x94B subunit is prepared for attachment to ring M. 4-Bromoaniline is protected as Boc-derivative and the coupled to 2-(t-butylamino)sulfonylphenylboronic acid under Suzuki conditions. 2-(t-Butylamino)sulfonylphenylboronic acid is prepared by the method described by Rivero (Bioorg. Med. Chem. Lett. 1994, 189). Deprotection with TFA can provide the aminobiphenyl compound. The aminobiphenyl is then coupled to the core ring structures as described below. 
When B is defined as Xxe2x80x94Y, the following description applies. Groups A and B are available either through commercial sources, known in the literature or readily synthesized by the adaptation of standard procedures known to practitioners skilled in the art of organic synthesis. the required reactive functional groups appended to analogs of A and B are also available either through commercial sources, known in the literature or readily synthesized by the adaptation of standard procedures known to practitioners skilled in the art of synthesis. In the tables that follow the chemistry required to effect the coupling of A to B is outlined.
The chemistry of Table A can be carried out in aprotic solvents such as a chlorocarbon, pyridine, benzene or toluene, at temperatures ranging from xe2x88x9220xc2x0 C. to the reflux point of the solvent and with or without a trialkylamine base.
The coupling chemistry of table B can be carried out by a variety of methods. The Grignard reagent required for Y is prepared from a halogen analog of Y in dry ether, dimethoxyethane or tetrahydrofuran at 0xc2x0 C. to the reflux point of the solvent. This Grignard reagent can reacted directly under very controlled conditions, that is low temperature (xe2x88x9220xc2x0 C. or lower) and with a large excess of acid chloride or with catalytic or stoichiometric copper bromide-dimethyl sulfide complex in dimethyl sulfide as a solvent or with a variant thereof. Other methods available include transforming the Grignard reagent to the cadmium reagent and coupling according to the procedure of Carson and Prout (Org. Syn. Col. Vol. 3 (1955) 601) or a coupling mediated by Fe(acac)3 according to Fiandanese et al. (Tetr. Lett. 1984, 4805), or a coupling mediated by manganese (II) catalysis (Cahiez and Laboue, Tetr. Lett. 1992, 33(31), 4437).
The ether and thioether linkages of Table C can be prepared by reacting the two components in a polar aprotic solvent such as acetone, dimethylformamide or dimethylsulfoxide in the presence of a base such as potassium carbonate, sodium hydride or potassium t-butoxide at a temperature ranging from ambient to the reflux point of the solvent used.
The thioethers of Table C serve as a convenient starting material for the preparation of the sulfoxide and sulfone analogs of Table D. A combination of wet alumina and Oxone can provide a reliable reagents for the oxidation of the thioether to the sulfoxide as shown by Greenhalgh (Syn. Lett. 1992, 235). The sulfone can be prepared according to the method of Satoh (Chem. Lett. 1992, 381) using m-chloroperbenzoic acid.
Scheme 3 describes the synthesis of compounds wherein M is a benzene ring and Q is a protected precursor of group D of Formula I and V is a nitro, protected sulfonamide or ester group and precursor of group Z of Formula I. The V group is placed on an appropriately substituted phenol either via nitration as shown by Poirier et al. (Tetrahedron 1989, 45(5), 1415), sulfonylation as shown by Kuznetsov (Akad. Nauk SSSR Ser. Khim 1990, 8, 1888) or carboxylation by Sartori et al. (Synthesis 1988, 10, 763). Bromination with triphenylphosphine and bromine (J. Am. Chem. Soc. 1964, 86, 964) gives the desired bromide. Suzuki coupling with the appropriate boronic acid provides the desired substituted pyridine. 
Schemes 4, 5, 6, and 7 describe the synthesis of compounds wherein M is pyridine and Q is a protected precursor of group D of Formula I. Each scheme represents a different substitution pattern for the pyridine ring. In Scheme 4, a suitably protected aldehyde is subjected to base-catalyzed condensation with an activated ester to give after deprotection the desired aldehyde. Refluxing with ammonium chloride as shown by Dornow and Ische (Chem. Ber. 1956, 89, 876) provides the pyridinol which is brominated with POBr3 (Tjeenk et al. Rec. Trav. Chim. 1948, 67, 380) to give the desired 2-bromopyridine. Suzuki coupling with the appropriate boronic acid provides the desired substituted pyridine. 
Treatment of an appropriately substituted 5-ethoxyoxazole with an alkene as shown by Kondrat""eva et al. Dokl. Akad. Nauk SSSR 1965, 164, 816) provides a pyridine with the V substituent at the para position. Bromination at the 3-position as shown by van der Does and Hertog (Rec. Trav. Khim. Pays-Bas 1965, 84, 951) followed by palladium-catalyzed boronic acid coupling provides the desired substituted pyridine. 
Scheme 6 describes a synthesis of a third substitution pattern on a pyridine ring. The appropriate tricarbonyl compound which can be prepared by methods described in Scheme 4 is treated with ammonium chloride to form the pyridinol which is subsequently brominated. Palladium-catalyzed coupling provides the desired substituted pyridine. 
Scheme 7 takes a suitably substituted dicarbonyl compound and by chemistry illustrated in Schemes 4 and 6, reacts it with ammonium chloride. Bromination gives the 3-bromopyridine which upon palladium-catalyzed coupling provides the desired substituted pyridine. 
Schemes 8, 9, and 10 describe the synthesis of compounds wherein M is pyridazine and Q is a protected precursor of group D of Formula I. Each scheme represents a different substitution pattern for the pyridine ring. In Scheme 8 an activated ester is reacted with an appropriately substituted xcex1-keto aldehyde and hydrazine as shown by Schmidt and Druey (Helv. Chim. Acta 1954, 37, 134 and 1467). Conversion of the pyridazinone to the bromide using POBr3 and palladium-catalyzed coupling provides the desired substituted pyridazine. 
In Scheme 9, glyoxal can react under basic conditions with an activated ketone and subsequently brominated/dehydro-brominated to give the desired ketoaldehyde. Alternatively, a protected ketone can react with an activated aldehyde, undergo bromination/dehydrobromination, be deprotected and oxidized to give the regioisomeric ketoaldehyde. Cyclization as shown by Sprio and Madonia (Ann. Chim. 1958, 48, 1316) with hydrazine followed by palladium-catalyzed coupling provides the desired substituted pyridazine. 
By analogy to Scheme 9, in Scheme 10 a aldehyde can be reacted with an activated ketone, brominated, dehydro-brominated and deprotected to give the desired diketone. Alternatively, a regioisomeric ketone can be placed through the same reaction sequence to produce an isomeric keto aldehyde. Reaction with hydrazine followed by palladium-catalyzed coupling provides the desired substituted pyridazine. 
Schemes 11, and 12 describe the synthesis of compounds wherein M is pyrimidine and Q is a protected precursor of group D of Formula I. Each scheme represents a different substitution pattern for the pyrimidine ring. In Scheme 11, a condensation with an appropriately substituted acid chloride and an activated ester followed by conjugate reduction by tin hydride (Moriya et al. J. Org. Chem. 1986, 51, 4708) gives the desired 1,4 dicarbonyl compound. Cyclization with formamidine or a substituted amidine followed by bromination gives the desired regioisomeric pyrimidine. Palladium-catalyzed coupling provides the desired substituted pyrimidine. 
Using similar chemistry, Scheme 12 shows how an amidine can be condensed with a 1,3-dicarbonyl compound and subsequently brominated in the 5-position (J. Het. Chem. 1973, 10, 153) to give a specific regioisomeric bromopyrimidine. Palladium-catalyzed coupling provides the desired substituted pyrimidine. 
Using the same ketoaldehyde from Scheme 12, cyclization with an appropriately substituted 1,2-diamine (Chimia 1967, 21, 510) followed by aromatization (Helv. Chim. Acta 1967, 50, 1754) provides a regioisomeric mixture of pyrazines as illustrated in Scheme 13. Bromination of the hydrobromide salt (U.S. Pat. No. 2,403,710) yields the intermediate for the palladium-catalyzed coupling step which occurs as shown above. 
Schemes 14 and 15 describe the synthesis of compounds wherein M is a 1,2,3-triazine and Q is a protected precursor of group D of Formula I. In Scheme 14, a vinyl bromide is palladium coupled to a molecule containing the substituent R1b. Allylic bromination followed by azide displacement provide the cyclization precursor. Triphenylphosphine-mediated cyclization (J. Org. Chem. 1990, 55, 4724) give the 1-aminopyrazole which is subsequently brominated with N-bromosuccimide. Lead tetraacetate mediated rearrangement as shown by Neunhoeffer et al. (Ann. 1985, 1732) provides the desired regioisomeric 1,2,3-triazine. Palladium-catalyzed coupling provides the substituted triazine. 
In Scheme 15, an alkene is allylically brominated and the bromide is displaced to give a regioisomer of the azide in Scheme 14. Following the same reaction sequence as shown above, cyclization provides the 1-aminopyrazole. Bromination followed by lead tetraacetate mediated rearrangement give the 1,2,3-triazine. Palladium-catalyzed coupling provides the other desired triazine. 
Schemes 16 and 17 describe the synthesis of compounds wherein M is a 1,2,4-triazine and Q is a protected precursor of group D of Formula I. In Scheme 16, a nitrile is converted using hydrazine to give the amidrazone which is condensed with a xcex1-ketoester to give the triazinone as shown by Paudler and Lee (J. Org. Chem. 1971, 36, 3921). Bromination as shown by Rykowski and van der Plas (J. Org. Chem. 1987, 52, 71) followed by palladium-catalyzed coupling provides the desired 1,2,4-triazine. 
In Scheme 16, to achieve the opposite regioisomer the reaction scheme shown above is modify by the substituting a protect xcex1-ketoester. This allows the most nucleophilic nitrogen to attack the ester functionality setting up the opposite regiochemistry. Deprotection and thermal cyclization gives the triazinone which is brominated as shown above. Palladium-catalyzed coupling provides the other desired 1,2,4-triazine. 
Scheme 18 describes the synthesis of compounds wherein M is a 1,2,3,4-tetrazine and Q is a protected precursor of group D of Formula I. Lithiation of a vinyl bromide, transmetallation with tin, palladium catalyzed carbonylation and hydrazone formation provides a diene for a subsequent Diels-Alder reaction as shown by Carboni and Lindsey (J. Am. Chem. Soc. 1959, 81, 4342). Reaction with dibenzyl azodicarboxylate followed by catalytic hydrogenation to debenzylate and decarboxylate should give after bromination the desired 1,2,3,4-tetrazine. Palladium-catalyzed coupling provides the desired substitution. 
Other features of the invention will become apparent in the course of the following descriptions of exemplary embodiments which are given for illustration fo the invention and are not intended to be limiting thereof.